Speaker:  Liang Xue (薛亮), European Molecular Biology Laboratory(EMBL)

Time: 15:00 pm, Janurary 4, 2023, GMT+8

Venue: Tecent Meeting ID: 680-594-703 Passcode: 0104

Abstract:

To delineate molecular machines in atomic detail inside cells represents the future of structural biology. Using cryo electron tomography (cryo ET) and sub tomogram analysis, I determined the ribosome structure at sub-3 A resolutions inside the human pathogen Mycoplasma pneumoniae cells. Extensive classification of ribosomes resolved more than 13 intermediate structures (4-10Aresolutions) along active translation, which not only visualizes their structural dynamics but also provides unique insights into their functional landscapes inside cells. Mapping back structures into the cellular tomogram reveals the spatial and functional organization of translating ribosomes, which enabled the discovery of a local coordination mechanism mediated by L9 within elongating polysomes. Moreover, I captured a variety of novel supramolecular assemblies formed by ribosomes and other molecular machines
including transcription-translation coupling complexes,ribosome-translocon complexes, and other supercomplexes that may only exist within the native cellular context. Furthermore, resolved more than 17 ribosome intermediate structures in three different antibiotic treated datasets, and demonstrated how small drug molecules drastically reshape the structural and functional landscapes of translation inside bacterial cells. These works pushed limits of cryo ET and sub tomogram analysis, and herald a new era of integrative in-cell structural biology.

Source: National Biomedical lmaging Center, Peking University